We describe the epidemiology of hospitalized RSV infections for all age groups from population-based surveillance in two rural provinces in Thailand.
From September 1, 2003 through December 31, 2007, ...we enrolled hospitalized patients with acute lower respiratory tract illness, who had a chest radiograph ordered by the physician, from all hospitals in SaKaeo and Nakhom Phanom Provinces. We tested nasopharyngeal specimens for RSV with reverse transcriptase polymerase chain reaction (RT-PCR) assays and paired-sera from a subset of patients with IgG enzyme immunoassay. Rates were adjusted for enrollment.
Among 11,097 enrolled patients, 987 (8.9%) had RSV infection. Rates of hospitalized RSV infection overall (and radiographically-confirmed pneumonia) were highest among children aged<1 year: 1,067/100,000 (534/100,000 radiographically-confirmed pneumonia) and 1-4 year: 403/100,000 (222/100,000), but low among enrolled adults aged≥65 years: 42/100,000. Age<1 year (adjusted odds ratio aOR=13.2, 95% confidence interval CI 7.7, 22.5) and 1-4 year (aOR=8.3, 95% CI 5.0, 13.9) were independent predictors of hospitalized RSV infection.
The incidence of hospitalized RSV lower respiratory tract illness among children<5 years was high in rural Thailand. Efforts to prevent RSV infection could substantially reduce the pneumonia burden in children aged<5 years.
Human metapneumovirus (HMPV) was recently identified in The Netherlands and was linked to acute respiratory tract illness. In this study, 11 isolates from 10 patients with respiratory disease from ...Quebec, Canada, were tested by a reverse-transcriptase polymerase chain reaction based on the fusion protein gene. Identified sequences were consistent with HMPV. The patients were 2 months to 87 years of age (median age, 58 years) and presented with acute respiratory tract illness during the winter season. Sequence studies of the nucleocapsid, fusion, and polymerase genes identified 2 main lineages of HMPV and cocirculation of both lineages during the same year. These findings support a previous finding that HMPV is a human respiratory pathogen that merits further study.
The virological features and clinical findings associated with the new human metapneumovirus (HMPV) were examined retrospectively in Canadian patients hospitalized for various respiratory conditions ...since 1993. Thirty-eight previously unidentified respiratory viruses isolated from rhesus monkey kindey (LLC-MK2) cells were found to be positive for HMPV by reverse-transcription polymerase chain reaction, and those strains clustered in 2 phylogenetic groups. Children aged <5 years and elderly subjects aged >65 years represented 35.1% and 45.9% of the HMPV-infected cases, respectively. In hospitalized children, the most frequent diagnoses were pneumonitis (66.7%) and bronchiolitis (58.3%), whereas bronchitis and/or bronchospasm (60%) and pneumonitis (40%) were most commonly seen in elderly subjects. Of the 15 patients with pneumonitis, 4 (26.7%) had immunosuppressive conditions and 6 (40%) were infants aged <15 months. These findings suggest that HMPV can be associated with severe lower-respiratory-tract infections in very young children, the elderly, and immunocompromised patients
Human respiratory syncytial virus (HRSV) is a major cause of serious lower respiratory tract illness in infants, young children, and the elderly. To characterize the circulation patterns of HRSV ...strains, nucleotide sequencing of the C-terminal region of the G protein gene was performed on 34–53 isolates obtained from 5 communities during 1 epidemic year, representing distinct geographical locations in North America. Phylogenetic analysis revealed that 5–7 HRSV genotypes, including 1 or 2 predominant strains, circulated in each community. The patterns of genotypes were distinct between communities, and less diversity was seen between strains of the same genotype within than between communities. These findings are consistent with HRSV outbreaks' being community based in nature, although transmission of viruses between communities may occur. Several strains are probably introduced or circulate endemically in communities each year, and local factors—possibly immunity induced by previous years' strains—determine which strains predominate during an HRSV season.
Human metapneumovirus is an emerging pathogen that causes upper and lower respiratory illness. Nursing home outbreaks of infection with this virus can cause severe illness and lead to poor patient ...outcomes. We report an outbreak investigation in a nursing home during 2018 and infection control guidelines to assist in disease control.
•A sensitive NGS assay for HRSV genomes was developed and validated.•Up to 96 samples could be combined in one run with genome coverage exceeding 99.3%.•Diverse HRSV genotypes were sequenced ...demonstrating methodologic robustness.
Human respiratory syncytial virus (HRSV) is a leading cause of acute respiratory illness in young children worldwide. Whole genome sequencing of HRSV offers enhanced resolution of strain variability for epidemiological surveillance and provides genomic information essential for antiviral and vaccine development. A 10-amplicon one-step RT-PCR assay and a 20-amplicon nested RT-PCR assay with enhanced sensitivity were developed to amplify whole HRSV genomes from samples containing high and low viral loads, respectively. Ninety-six HRSV-positive samples comprised of 58 clinical specimens and 38 virus isolates with Ct values ≤ 24 were amplified successfully using the 10-amplicon one-step RT-PCR method and multiplexed in a single MiSeq run. Genome coverage exceeded 99.3% for all 96 samples. The 20-amplicon nested RT-PCR NGS method was used to generate >99.6% HRSV full-length genome for 72 clinical specimens with Ct values ranging from 24 to 33. Phylogenetic analysis of the genome sequences obtained from the 130 clinical specimens revealed a wide diversity of HRSV genotypes demonstrating methodologic robustness.
•Current nucleotide sequences ensure the reliability of rRT-PCR assays.•Development of a duplex rRT-PCR assay for the distinction of HRSV subgroups A and B.•Assay validation used an established ...pan-HRSV rRT-PCR as a reference test.•HRSV investigations and surveillance studies as duplex assay potential applications.
Human respiratory syncytial virus (HRSV) is a leading cause of acute respiratory illness in young children worldwide. Reliable detection and identification of HRSV subgroup A and B infections are essential for accurate disease burden estimates in anticipation of licensure of novel HRSV vaccines and immunotherapies. To ensure continued reliability, molecular assays must remain current with evolving virus strains. We have developed a HRSV subgroup-specific real-time RT-PCR (rRT-PCR) assay for detection and subgroup identification using primers and subgroup-specific probes targeting a conserved region of the nucleoprotein gene combined in a single duplex reaction using all genome sequence data currently available in GenBank. The assay was validated for analytical sensitivity, specificity, reproducibility, and clinical performance with a geographically diverse collection of viral isolates and respiratory specimens in direct comparison with an established pan-HRSV rRT-PCR reference test. The assay was sensitive, reproducibly detecting as few as 5–10 copies/reaction of target RNA. The assay was specific, showing no amplification with a panel of 16 other common respiratory pathogens or predicted by in silico primer/probe analysis. The duplex rRT-PCR assay based on the most current available genome sequence data permits rapid, sensitive and specific detection and subgroup identification of HRSV.
Human bocavirus species 2 and 3 in Brazil Santos, Norma; Peret, Teresa C.T; Humphrey, Charles D ...
Journal of clinical virology,
06/2010, Letnik:
48, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Abstract Background The newly described human bocavirus (HBoV) species 2 and 3 have been repeatedly detected in stool strengthening the possibility that these viruses might present a tropism for the ...gastrointestinal tract and may be etiological agents of diarrhea. Objective In this study we assessed the presence of HBoV2 and HBoV3 in stool specimens from Brazilians with acute gastroenteritis. Study design Stool samples from Brazilian patients with acute diarrhea were analyzed for HBoV2 and HBoV3 by PCR assay. Full or partial genome sequences were obtained for selected isolates. Electron microscopy analysis was used to investigate virus morphology. Results Electron microscopy confirmed the presence of virus-like particles in HBoV PCR-positive specimens, with morphology similar to other members of the Parvoviridae family. Five samples out of 807 (0.6%) were positive for HBoV3. Three of the HBoV3-positive patients were HIV/AIDS positive. A selected group of 144 samples was also tested for HBoV2 and 30 samples (20.8%) were positive, 11 of which were HIV/AIDS positive. Conclusion This study reports the detection and genetic characterization of HBoV3 and HBoV2 in the stool of Brazilian patients with acute diarrhea. This is the first description of HBoV3 outside Australia, suggesting a wide global distribution of this virus. Further studies are needed to better understand the role of HBoV in gastrointestinal infections, particularly among patients with HIV/AIDS.
This study identified a genotype of respiratory syncytial virus (RSV) associated with increased acute respiratory disease severity in a cohort of previously healthy term infants. The genotype ...(2stop+A4G) consists of two components. The A4G component is a prevalent point mutation in the 4th position of the gene end transcription termination signal of the G gene of currently circulating RSV strains. The 2stop component is two tandem stop codons at the G gene terminus, preceding the gene end transcription termination signal. To investigate the biological role of these RSV G gene mutations, recombinant RSV strains harboring either a wild-type A2 strain G gene (one stop codon preceding a wild-type gene end signal), an A4G gene end signal preceded by one stop codon, or the 2stop+A4G virulence-associated combination were generated and characterized. Infection with the recombinant A4G (rA4G) RSV mutant resulted in transcriptional readthrough and lower G and fusion (F) protein levels than for the wild type. Addition of a second stop codon preceding the A4G point mutation (2stop+A4G) restored G protein expression but retained lower F protein levels. These data suggest that RSV G and F glycoprotein expression is regulated by transcriptional and translational readthrough. Notably, while rA4G and r2stop+A4G RSV were attenuated in cells and in naive BALB/c mice compared to that for wild-type RSV, the r2stop+A4G RSV was better able to infect BALB/c mice in the presence of preexisting immunity than rA4G RSV. Together, these factors may contribute to the maintenance and virulence of the 2stop+A4G genotype in currently circulating RSV-A strains.
Strain-specific differences in respiratory syncytial virus (RSV) isolates are associated with differential pathogenesis in mice. However, the role of RSV genotypes in human infection is incompletely understood. This work demonstrates that one such genotype, 2stop+A4G, present in the RSV attachment (G) gene terminus is associated with greater infant disease severity. The genotype consists of two tandem stop codons preceding an A-to-G point mutation in the 4th position of the G gene end transcription termination signal. Virologically, the 2stop+A4G RSV genotype results in reduced levels of the RSV fusion (F) glycoprotein. A recombinant 2stop+A4G RSV was better able to establish infection in the presence of existing RSV immunity than a virus harboring the common A4G mutation. These data suggest that regulation of G and F expression has implications for virulence and, potentially, immune evasion.
Abstract
An immunocompetent adult with asthma developed severe human metapneumovirus (HMPV) illness complicated by group A Streptococcus coinfection, progressing to acute respiratory distress ...syndrome and shock. Several coworkers had less severe HMPV infection. HMPV can cause severe respiratory illness in healthy adults and should be considered as a potential cause of community respiratory outbreaks.
PDF
